A lovers’ quarrel turned deadly yesterday when a crazed man shot three generations of Bronx women – leaving his girlfriend clinging to life, her mother dead and grandmother seriously injured before turning the gun on himself, authorities said.

Sheldon Harris – who has a two-year-old daughter with his gal pal, Colleen Brown – allegedly began his shooting spree by opening fire at the young woman in the stairwell of her home on East 233rd Street in Wakefield just after 11 a.m.

Then, police said, he charged upstairs and unloaded a barrage of bullets at her family.

“When the first shot went off, [Colleen] screamed and then she said ‘Call the police! Call the police!’ ” said a neighbor who did not want to be identified.

Brown, 24, was shot in the chest, stomach and leg. Her mother, Joan, 53, was hit once in the chest and her grandmother, who family identified as Clarissa, 74, was shot in the torso.

Harris then tried unsuccessfully to kill himself by firing three bullet into his chest.

The wild-eyed triggerman spared his daughter, Taylor, according to police sources who said the toddler was in the apartment during the gunfire and is being cared for by relatives.

The three women were rushed to Jacobi Hospital, where Joan was pronounced dead and Clarissa was in critical condition. Colleen was fighting for her life.

Harris also was in critical condition.

More than a dozen reeling friends and family members huddled at the hospital yesterday, where Joan’s son happens to work as a nurse.

Clarissa’s niece, Alicia Bryan, bolted from her Mount Vernon home the moment she heard about the attack.

“I dropped everything and came over,” she said. “You don’t really cry, you just go into shock.”

Joan’s brother, who declined to give his name, said the family is “still in limbo” as they await news on the wounded women.

It was not immediately clear what triggered Harris’ rage.

Family friend Junior Clarke said Colleen’s murdered mother had never wanted Harris around.

“She really can’t stand him,” said Clarke, who noted the couple had been arguing back and forth for a while.

“[The mother] used to keep him outside the house – she wouldn’t let him in.”

Neighbors said they constantly saw the couple at each other’s throats.

One claimed he’d been stalking her and had been lurking around the building for the past week.

Another neighbor said Brown – who worked at a children’s clothing store and attended Westchester Community College – was sitting in Harris’ car a few months ago and, “I heard them out there yelling back and forth. Then he hit her.”